DL 1248 then DL 543 at Atlanta
Harrisburg → Atlanta → St Louis
Timetable, Atlanta time
16:08DL 1248 from Harrisburg at the gate
15:45DL 543 to St Louis leaves the gate
23 h 37 apart on the timetable, overnight
DL 543 leaves 23 h 37 after DL 1248 arrives on the timetable: more than half a day, so not a connection we count.